Mechanisms of neurodegeneration in Parkinson disease: several members of the tetrahydroisoquinoline (TIQ) family of monoamine alkaloids can be formed from dopamine or its oxidized metabolites and may be involved in the pathogenesis of monoaminergic cell death in Parkinson disease. To examine the potential role of TIQs in monoaminergic cell death, we have used enantiomeric-selective high-performance liquid chromatography with electrochemical detection, liquid chromatography with tandem mass spectroscopy, cell culture studies of neurotoxicity and assays of mitochondrial membrane potential.

The neural networks mediating suprasegmental control of the blink reflex and spontaneous blinking remain poorly understood. Viral transneuronal tracing is being used to define the integrated premotor cortical and subcortical control of levator palpebrae and orbicularis oculi motoneuron activity.

In isolation or via interactions with striatal-thalamo-cortical pathways, olivocerebellar structures play a critical role in disorders of motor control such as ataxia and dystonia. Using neurophysiological and molecular tools, we are dissecting the relative roles of individual network elements in the positive and negative signs characteristic of individual movement disorders.